+static int
+inet6_addr_modify(int ifindex, struct in6_addr *pfx,
+ __u32 prefered_lft, __u32 valid_lft)
+{
+ struct inet6_ifaddr *ifp = NULL;
+ struct net_device *dev;
+ int ifa_flags = 0;
+
+ if ((dev = __dev_get_by_index(ifindex)) == NULL)
+ return -ENODEV;
+
+ if (!(dev->flags&IFF_UP))
+ return -ENETDOWN;
+
+ if (!valid_lft || (prefered_lft > valid_lft))
+ return -EINVAL;
+
+ ifp = ipv6_get_ifaddr(pfx, dev, 1);
+ if (ifp == NULL)
+ return -ENOENT;
+
+ if (valid_lft == INFINITY_LIFE_TIME)
+ ifa_flags = IFA_F_PERMANENT;
+ else if (valid_lft >= 0x7FFFFFFF/HZ)
+ valid_lft = 0x7FFFFFFF/HZ;
+
+ if (prefered_lft == 0)
+ ifa_flags = IFA_F_DEPRECATED;
+ else if ((prefered_lft >= 0x7FFFFFFF/HZ) &&
+ (prefered_lft != INFINITY_LIFE_TIME))
+ prefered_lft = 0x7FFFFFFF/HZ;
+
+ spin_lock_bh(&ifp->lock);
+ ifp->flags = (ifp->flags & ~(IFA_F_DEPRECATED|IFA_F_PERMANENT)) | ifa_flags;
+
+ ifp->tstamp = jiffies;
+ ifp->valid_lft = valid_lft;
+ ifp->prefered_lft = prefered_lft;
+
+ spin_unlock_bh(&ifp->lock);
+ if (!(ifp->flags&IFA_F_TENTATIVE))
+ ipv6_ifa_notify(0, ifp);
+ in6_ifa_put(ifp);
+
+ addrconf_verify(0);
+
+ return 0;
+}
+